Toroidal coil winding machine



Nov. 5, 1957 J. R. GOODYKOONTZ, JR 2,812,143

TOROIDAL con. WINDING MACHINE Filed may 23, 1956 A TTORNEY United StatesPatent TOROIDAL COIL WINDING MACHINE James R. Gpodykoontz, J12, Venice,Califi, assignor to Hughes Aircraft Company, Culver City, Calif., acorporation of Delaware Application May 23, 1956, Serial No. 586,872

12 Claims. (Cl. 242--4) inaccurate and mechanical winding by means ofWirecarrying bobbins has been impractical due primarily to therelatively small sizes of toroidal coils that have become necessary incontemporary electrical and electronic circuitry. It is not uncommon,for example, in miniaturized electrical devices, to employ toroidalcoils that are in the nature of one-eighth of an inch in overalldiameter, having a central opening of approximately onesixteenth of aninch. In such instances, it has heretofore been practically impossibleto pass the wire-carrying bobbin through the opening in the toroidalcore for several reasons such as, for example, the necessity forsupporting and moving a bobbin or shuttlearrangement while stillpermitting passage thereof through the central core opening. In general,prior mechanisms have been either too large, too heavy or propelled insuch a manner as to prohibit their use in mechanical winding of thesmall toroidal cores.

It is, therefore, an object of the present invention to provide amachine for winding toroidal coils of relatively small diameter.

It is another object of the present invention to provide a machine forWinding toroidal coils by means of a sewing action.

' It is a further object of the present invention to provide a machinethat winds wire onto a toroidal core of relatively small diameter bymeans of a wire-threaded needle that is periodically passed through thecentral opening of the core under the control of a magnetic field.

1 The toroidal coil Winding machine of the present invention overcomesthe limitations of machines found in the prior art by employing a newwinding technique. More particularly, in the machine of the presentinvention, fine copper wire is wound onto miniature toroidal cores witha simple sewing action which is accomplished by threading a length ofthe wire onto a sewing needle and causing the needle to move in acircular path on a suitable horizontal working surface by means of aperman'ent magnet which is moved in a circular path directly beneath theWorking surface. The toroid is positioned so th at its axis coincideswith the path of the needle at a chosen point in the path with theresult that with each revolution of the magnet the needle passes throughthe toroid, thereby wrapping a turn of wire onto the toroid. It will beobvious that for all practical purposes, the only limitation on thesmallness of the central opening or, stated diiferently, the innerdiameter of the toroid is the needle itself, the thinner the needleutilized the smaller the obtainable inner diameter.

The novel features which are believed to be characteris'tic-of theinvention, both as to its organization and ICE method of operation,together with further objects and advantages thereof, will be betterunderstood from the following description considered in connection withthe accompanying drawings in which an embodiment of the invention isillustrated by way of example. It is to be expressly understood,however, that the drawings are for the purpose of illustration anddescription only, and are not intended as a definition of the limits ofthe invention.

Fig. l is a perspective view of one embodiment of a toroidal coilWinding machine in accordance with the present invention;

Fig. 2 is a top view of the machine of Fig. 1 illustrating the pathtaken by the wire-threaded needle, the operation of the turn-tightenerand the function of the needle guide, the parts of the machineunessential for such an illustration being omitted for purposes ofclarity; and

Fig. 3 is a cross-sectional view of the machine of Fig. 1 taken alongthe lines 3-3 of Fig. 2.

Referring now to the drawings, there is shown in Fig. l a machine forwinding an electrical wire 10 upon a toroidal core 11 having arelatively small inner diameter. As shown in the figure, the machinebasically comprises a baseboard 12, a sewing needle 13, a permanentmagnet 14, a turn-tightener mechanism, generally designated 15, ananti-kinking device 16, a needle guide 17, and means, generallydesignated 18, for holding and rotating core 11 as wire 19 is wound uponit.

Baseboard 12 is made of a non-magnetic material and has a smooth upperworking surface. In addition, baseboard 12 has a relatively largecircular opening 20 and a slot 21 wherein core 11 is positioned.Baseboard 12 is preferably fiat and preferably maintained in ahorizontal position. I

Sewing needle 13 is no different than any other sewing needle exceptthat, of necessity, it is made of a magnetic material, such as steel.freely on the smooth upper working surface of basebaord 12 and isthreaded with wire 10.

Permanent magnet 14 is positioned beneath baseboard 12 and contiguous tothe lower surface thereof in order that the magnetic field produced bythe magnet may be applied through the baseboard to the upper workingsurface whereon needle 13 rests. Magnet 13 is mechanically coupled to amotor 22 which continuously moves the magnet in a circular path aboutthe motor shaft as indicated by arrows 23 in Fig. 2.

Turn-tightener mechanism v1.5 is provided topull the turns of wire woundon core 11 to the desired degree of tightness and, as shown in thefigure, comprises a turntable 24 connected directly to the shaft ofmotor 22 that turns magnet 14. Turntable 24 is positioned in hole 20, ofbaseboard 1.2 and is flush with the upper Working. surface of thebaseboard. Turn-tightener mechanism 15 further includes a rubber-rimmedwheel 25 resiliently mounted at one end of an arm 26, the other end ofthe arm being rigidly fixed in position. Wheel 25 engages turntable 24and, since the turntable is rotated by motor 22, the wheel is alsocaused .to rotate since the latter is free to turn on its shaft.Moreover, it will be noted that wheel 25 is canted so that its outeredge is lifted above the turntable surface. Such an arrangementfacilitates the passage of wire '10 under wheel 25. The canting of thewheel may be seen from Fig. 1 and more specifically from Fig. 3.

Anti-kinking device 16 is preferably a sheet of nonmagnetic materialpositioned above the upper surface of baseboard 12 and, as is apparentfrom the figures, parallel and contiguous thereto. Sheet 16 has acircularopening 27 through it of approximately the same diameter ascircular opening 20 of..baseboard.12. Circular opening" Sewing needle 13rests 27 overlies opening so that wheel may be Permitted to come intocontact with turntable 24. Thus, sheet 16 almost entirely covers theportion of the working surface of baseboard 12 upon which wire 10 maymove, thereby preventing the wire from looping or kinking.

Needle guide 17 is employed to guide needle 13 in a positive mannerimmediately preceding its entry into core 11. More specifically, needleguide 17 is utilized to assure 'that needle 13 will pass through thecenter of core 11 if either the radial position of magnet 14 changesslightly with use or the position of the needle changes with respect tothe magnet. This is done by mounting guide device 17 on baseboard 12 inthe circular path of movement of the needle as is clearly shown in Fig.2. The needle is deflected by guide 17 and is thereafter positivelydirected in a straight line toward the center of the core.

Means 18 for rotating core 11 basically comprises a rack 28 movablymounted between an idler gear 30 and a drive gear 31 coupled by means ofa shaft to a motor 32. Means 18 also includes an additional pair ofidler gears 33 and 34 between which core 11 is positoined as is clearlyshown in the figures. Rack 28 rests at one end on core 11 and as therack is slowly moved by means of drive gear 31 and motor 32, the core isslowly rotated about its axis, thereby permitting wire 10 to bedistributed on the core. Obviously, the speeds of motors 22 and 32 maybe synchronized so that core 11 is rotated at such a speed relative tothe speed of rotation of needle 13 that the wire is uniformly wound onthe core.

Considering now the operation, a length of wire 10 is threaded ontoneedle 13, a toroid core 11. is positioned between idler gears 33 and 34and motors 22 and 32 are turned on. As a result, magnet 14 is driven ina circle by motor 22 and needle 13, which has been placed on the workingsurface of baseboard 12 so that it lies in the field of the magnet,follows the magnet and, thereby, tends to describe a circular path. Thecircular path followed by magnet 14 as well as the circular path soughtto be followed by needle 13 is indicated by arrows 23 in Fig. 2.

With each complete revolution of magnet 14, needle 13 passes through thecentral opening of core 11, thereby wrapping or winding a turn of wireonto the core. More specifically, during each rotation of needle 13, theneedle is deflected at one point in its path by needle guide 17 whichcauses the needle to travel in a straight line immediately prior to andduring its entry into the core. Since the straight line path of needle13 is determined by guide 17, it is, therefore, substantiallyindependent of the normal circular path defined by the field of themoving magnet. Thus, once the toroid core is positioned with respect tothe needle guide, no great attention need thereafter be paid to the pathwhich the needle would take without the guide. In other words, tolerancerequirements on the magnet driving and positioning mechanism and thefield configuration of the magnet are thereby greatly reduced with theresult that the machine is easier to build and less likely to get out ofalignment during operation.

At the same time that the wire winding operation is going on, motor 32slowly rotates core 11 about the latters axis at a speed that is apredetermined fraction of the rotational speed of magnet 14. Stateddifferently, the speed of motor 32 may be synchronized in such a mannerwith the speed of motor 22 that the core, driven by motor 32 throughrack 28 and gear 31, is rotated through a small angle during eachrevolution of the magnet. As a consequence, wire 10 is distributed aboutcore 11 and uniformly wound thereon.

It will be obvious that the only force ordinarily available for pullingthe turns of wire tight about core 11 is the force exerted on needle 13by magnet 14 and that .{While this magnetic force is sutficient to movethe needle and wire, it may not be suflicient to pull the individualturns of wire to the desired degree of tightness.

Turn-tightener mechanism 15 provides the additional force that mayberequired for'pulling the wire tight.

Since turntable 24 is coupled to motor 22, the turntable is also rotatedin the same direction as magnet 14. Furthermore, since rubber-rimmedwheel 25 engages turntable 24, the rotation of the turntable causes thewheel to rotate. Thus, when wire 10 passes between turntable 24 andwheel 25, as it does during each rotation of needle 13, the wire ismoved slightly to the right with the result that a slight tug occurswhich pulls the wire tight about the core.

It will also be obvious that unless suitable preventative measures aretaken, wire 10 may loop or kink during the winding operation due to thefact that for half of each cycle the wire is in a slack condition andessentially uncontrolled. The kinking difficulty is overcome byantikinking device 16 which constrains the wire to lie essenthe core bydriving it, through suitable gearing, from the magnet motor.

Having thus described the invention, what is claimed as new is:

1. A machine for winding wire onto a toroidal core, said machinecomprising: a baseboard having a smooth working surface on one sidethereof and a slot therethrough wherein the core is positioned, the corebeing oriented in such a manner that the core axis is substantiallyparallel to said working surface; a magnet movably positioned. on theother side of said baseboard and contiguous thereto; a sewing needle,made of a magnetic material and threaded with the wire to be wound onthe toroidal core, resting on the working surface in the magnetic fieldof said magnet, said sewing needle being movable under the influence ofsaid magnet along a path on said surface corresponding to the path ofmovement of said magnet; and means for continuously moving said magnetin a predetermined closed path such that said needle is successivelymoved through the center of the core, whereby a turn of wire is woundupon the core with each passing of said needle through the core.

2. A machine for winding wire onto a toroidal core, said machinecomprising: a baseboard made of a nonmagnetic material and having asmooth working surface on one side thereof, said baseboard having anopening therethrough wherein the core is positioned; means for producinga magnetic field through said baseboard to said working surface, saidmeans being movably positioned ontthe other side of said baseboard andcontiguous thereto; a sewing needle resting on the working surface ofsaid baseboard and threaded with the wire to be wound on the core, saidneedle being made of a magnetizable material and, under the influence ofthe magnetic field, being movable along said surface in a pathcorresponding to the path of movement of said means; and means forcontinuously moving said last-named means in a predetermined closed pathsuch that said needle recurrently passes through the center of the core,one turn of wire being wound uponthe core with each such passage of saidneedle.

3. A machine for winding wire onto a toroidal core, said machinecomprising: a baseboard made of a nonmagnetiomaterial and having asmooth working surface on one side thereof, said baseboard having anopening therethrough wherein the'core is positioned; a magnet movablypositioned on the other side of said baseboard and contiguous theretofor applying a magnetic field through said baseboard to the workingsurface; a sewing needle resting on the working surface of saidbaseboard in the field'of said magnet and threaded with the wire to beWound on the core, said needle being made of a magnetic material and,under the influence of the magnetic field, movable along said surface ina path corresponding to the path of movement of said magnet; drive meansforcontinuously moving said magnet in a predetermined closed path suchthat said needle recurrently passes through the center of the core, oneturn of wire being wound upon the core with each such passage of saidneedle; and additional means for rotating the core in such a manner thatthe turns of wire are uniformly distributed about the core.

4. A machine for winding wire onto a toroidal core, said machinecomprising: a baseboard made of a nonmagnetic material and having asmooth working surface on one side thereof, said baseboard having anopening therethrough wherein the core is positioned; means for producinga magnetic field through said baseboard to said working surface, saidmeans being movably positioned on the other side of said baseboard andcontiguous thereto; drive means for continuously moving said magneticfield producing means in a circular path; a sewing needle resting freelyon the working surface of said baseboard and threaded with the wire tobe wound on the core, said needle being made of a magnetic material and,under the influence of the magnetic field, moved along said surface in acircular path corresponding to the circular path of movement of saidmeans; and a guide device mounted on said working surface and positionedin the circular path of movement of said needle for deflecting saidneedle during each rotation thereof positively to guide said needlethrough the center of the core.

5. A machine for winding wire onto a toroidal core, said, machinecomprising: a flat horizontally positioned baseboard made of anon-magnetic material and having a smooth upper working surface, saidbaseboard having an opening therein wherein the core is positioned;means for producing a magnetic field, said means being rotatablypositioned beneath said baseboard and contiguous to the lower surfacethereof for applying the magnetic field through said baseboard to saidupper working surface; drive means for continuously rotating said meansin a circular path; a sewing needle resting freely on the upper surfaceof said baseboard and threaded with the wire to be wound on the core,said needle being made of a magnetic material and, under the influenceof the magnetic field, moved along said smooth upper surface in asubstantially circular path corresponding to the circular path ofmovement of said means; a guide device mounted on said baseboard andpositioned in the circular path of movement of said needle fordeflecting said needle during each rotation thereof positively to guidesaid needle toward the center of the core; and a flat sheet ofnon-magnetic material positioned parallel to said baseboard andcontiguous to the working surface thereof for preventing the wire fromkinking.

6. A machine for winding wire onto a toroidal core, said machinecomprising: a flat horizontally positioned baseboard made of anon-magnetic material and having a smooth upper working surface, saidbaseboard having an opening therein wherein the core is positioned; amagnet rotatably positioned beneath said baseboard and contiguous to thelower surface thereof for applying a magnetic field through saidbaseboard to said upper working surface; drive means for continuouslyrotating said magnet in a circular path; a sewing needle resting on theWorking surface of said baseboard in the field of said magnet andthreaded with the wire to be wound on the core, said needle being madeof a magnetic material and, under the influence of the magnetic field,moved along said surface in a substantially circular path correspondingto the circular path of movement of said magnet; a guide device mountedon said baseboard and positioned in the circular path of movement ofsaid needle for deflecting said needle during each rotation thereofpositively to guide said needle through the center of the core, one

turn of wire being wound upon the core with each passing of said needlethrough the core; additional means for rotating the core in such amanner that the turns of wire are uniformly distributed about the core;and a flat sheet of non-magnetic material positioned parallel to saidbaseboard and contiguous to the working surface thereof for preventingthe wire from kinking.

7. A machine for winding wire onto a toroidal core, said machinecomprising: a baseboard having a smooth working surface on one sidethereof and a slot therethrough wherein the core is positioned; meansfor producing a magnetic field through said baseboard to said Workingsurface, said means being movably positioned on the other side of saidbaseboard and contiguous thereto; a sewing needlevmade of a magneticmaterial resting on the working surface of said baseboard in themagnetic field produced therethrough, said needle, under the influenceof the magnetic field, being movable along said surface in a pathcorresponding to the path of movement of said means; drive means forcontinuously moving said magnetic field producing means in apredetermined closed path such that said needle recurrently passesthrough the center of the core, one turn of wire being wound upon thecore with each such passage of said needle; and a turn-tightenermechanism for applying a slight tug to each turn of wire as it is woundupon the core, thereby to pull the individual turns to the desireddegree of tightness.

8. A machine for winding wire onto a toroidal core, said machinecomprising: a baseboard having a smooth Working surface on one sidethereof and a slot therethrough wherein the core is positioned; meansfor producing a magnetic field through said baseboard to said workingsurface, said means being movably positioned on the other side of saidbaseboard and contiguous thereto; a sewing needle made of a magneticmaterial resting on the Working surface of said baseboard in themagnetic 'field therethrough, said needle, under the influence of themagnetic field, being movable along said surface inla path correspondingto the path of movement of said means; drive means for continuouslymoving said magnetic field producing means in a predetermined closedpath such that said needle recurrently passes through the center of thecore, one turn of wire being wound upon the core with each such passageof said needle; a turn-tightener mechanism for applying a slight tug toeach turn of wire as it is wound upon the core, thereby to pull theindividual turns to the desired degree of tightness; and means forpreventing the wire from kinking during the Winding operation.

9. The machine defined in claim 8 wherein said means for preventing thewire from kinking comprises a sheet of non-magnetic material positionedin spaced parallel relationship to said baseboard and contiguous to theWorking surface thereof.

10. A machine for winding wire onto a toroidal core, said machinecomprising: a baseboard made of a nonmagnetic material and having asmooth working surface on one side thereof, said baseboard having anopening therethrough wherein the core is positioned; a magnet movablypositioned on the other side of said baseboard and contiguous theretofor applying a magnetic field through said baseboard to said workingsurface; drive means for continuously moving said magnet in a circularpath; a sewing needle made of a magnetic material resting freely on saidworking surface in the field of said magnet, said needle being threadedwith the wire to, be wound on the core and, under the influence of themagnetic field, moved along said surface in a circular pathcorresponding to the circular path of movement of said magnet; a guidedevice mounted on said working surface and positioned in the circularpath of movement of said needle for deflecting said needle in such amanner during each rotation thereof positively as to guide said needlethrough the center of the core, thereby to we the core, thereby to pullthe individual turns to the desired degree of tightness.

11. A machine for Winding wire onto a toroidal core, said machinecomprising: a baseboard made of a nonmagnetic material and having asmooth Working surface on one side thereof, said baseboard having anopening therethrough wherein the core .is positioned; a magnet movablypositioned on the other side of said baseboard and contiguous theretofor applying a magnetic field through said baseboard to said workingsurface; drive means for continuously moving said magnet in a circularpath; a sewing needle made of a magnetic material resting freely on saidworking surface in the field of said magnet, said needle being threadedwith the wire to be wound on the core and, under the influence of themagnetic field, moved along said surface in a circular pathcorresponding to the circular path of movement of said magnet; a guidedevice mounted on said working surface and positioned in the circularpath of movement of said needle for deflecting said needle in such amanner during each rotation thereof positively as to guide said needlethrough the center of the core, thereby to successively 'wind turns ofwire onto the core; means for rotating the core in such a manner thatthe turns of wire are uniformly distributed about the core; apparatusfor preventing the wire from kinking during the winding operation, and aturn-tightener mechanism for applying a relatively slight tug to eachturn of wire after being wound upon the core, thereby to pull theindividual turns to -the desired degree of tightness.

12. A machine for winding wire onto a toroidal core, said machinecomprising: a baseboard made of a nonmagnetic material and having asmooth working surface on one side thereof, said baseboard having afirst circular opening therethrough and a slot wherein the core ispositioned; a magnet rotatably positioned on the other side "of saidbaseboard and contiguous thereto for applying a magnetic field throughsaid baseboard to the working surface; drive means for continuouslyrotating said mag net in a circular path about the first circularopening; a sewing needle resting freely on the working surface in thefield'of the magnet and threaded with the wire to be wound on the core,said needle being made of a magnetic material and, under the influenceofthe magnetic field, moved along the working surface about the firstcircular opening in a substantially circular path corresponding to thecircular path of movement of said magnet; a guide device mounted on saidbaseboard and positioned in the circular path of movement of said needle"for defiecting said needle during each rotation thereof tpositively toguide said needle through the center of 'the'core, one turn of-wirebeing wound upon the core with each passing of said ne'edle through thecore; means for rotating the core in such a manner that the turns ofwire are uniformly distributed about the core; a sheet of non-magneticmaterial Positioned parallel to said baseboardand contiguous to theworking surface thereof for preventing the wire from kinking, said sheethaving a second circular opening therethrough overlying the firstcircular opening of said baseboard; and a turn-tightener mechanism forapplying a slight tug to each turn of wire as it is wound upon the core,thereby to pull the individual turns to the desired degree of tightness,said turntightener mechanism including a turntable mechanically coupledto said drive means and positioned in the first circular opening of saidbaseboard in the plane thereof, and a rubber-rimmed wheelrotatablymounted on the one side of said baseboard in such a manner that the rimof said wheel is at all times in contact with said turntable.

2,192,694 Quinlan Mar. 5,'l940

